Duplicating machines



Feb. 6, 1962 J. L. ROGERS 3,019,726

DUPLICATING MACHINES Filed March 24, 1959 5 Sheets-Sheet l Jsse Z age/Ls Feb. 6, 1962 J. L. ROGERS DUPLICATING MACHINES 5 Sheets-Sheet 2 Filed March 24. 1959 finite 3,619,726 Patented Feb. 6, 1962 3,019,726 DUPLICATING MACHINES Jesse L. Rogers, 2014 Connecticut Ave., Washington, D.C. Filed Mar. 24, 1959, Ser. No. 891,552 Claims. (Cl. 101-432) This invention relates to new and useful improvements in duplicating machines such as are used for reproducing one or more copies by impression from a master mounted upon a rotary cylinder.

In the use of such machines it is often desirable to block out a certain portion or portions of the data appearing on the master so that such portion or portions are not reproduced on the copies. In conventional practice, such blocking out is accomplished by positioning a piece of blocking or masking material against the area of the master which is to be blocked out and adhesively, magnetically or otherwise securing the masking material in position. This procedure, however, is not only difiicult and time consuming, but often results in error and waste when the masking material accidentally shifts its position. Moreover, in some instances the masking ma. terial permanently damages the master so that the latter is not subsequently usable en toto.

The principal object of this invention is to completely eliminate the various disadvantages above outlined, this being attained by the provision of means for quickly, easily and dependably blocking out any desired portion or portions of the master without the use of any masking material whatever.

Conventional duplicating machines usually employ an impression roller for pressing the copy against the master on the rotary cylinder, it being understood, of course, that in the absence of such pressure, an impression from the master on the copy would not be possible. The

resent invention concerns itself primarily with a novel structurai arrangement of the impression roller which, rather than being unitary as in the past, in this instance consists of a plurality of individual sections disposed in substantial axial alignment longitudinally of the cylinder.

The roller sections are individually and independently movable in and out of cooperating relation with the cylinder, that is, so that they either press or do not press against the cylinder, and since the individual roller sections act only on the respective areas of the copy with which they come in contact, it will be apparent that any desired area or areas of the master may be prevented from reproducing on the copy by simply moving the appropriate section or sections of the impression roller out of its cooperating relation with the cylinder.

An important feature of the invention resides in the provision of novel means for movably holding the individual impression roller sections and electro-magnetic means for selectively moving the same to their inoperative or blocking out position.

Another important feature of the invention resides in the provision of switch means for energizing the aforementioned electro-magnetic means, such switch means comprising a plurality of individual switches disposed in a novel keyboard arrangement which permits any one switch to be actuated alone, or several switches actuated simultaneously in a group.

Another feature of the invention involves the provision of means for quickly and easily cancelling the setting of the impression roller sections after a run of the desired number of copies from the master, whereupon the switch keyboard may again be actuated to block out the same or other areas of the master, as desired.

Another feature of the invention resides in the provision of means for retaining a particular group setting of switches for blocking out particular areas, such group setting being obtainable repeatedly, even after actuation of the aforementioned cancelling means, by energlzation of only one switch in the entire group.

Some of the advantages of the invention reside in its simplicity of construction, easy, convenient and dependable operation, and in its adaptability for embodiment lIl duplicating machines of various sizes and types.

With the foregoing more important objects and features in view and such other objects and features as may become apparent as this specification proceeds, the invention will be understood from the following description taken in conjunction with the accompanying drawings, wherein like characters of reference are used to designate like parts, and wherein: a

FIGURE 1 is a fragmentary top plan view of a duplieating machine embodying the invention;

FIGURE 2 is a fragmentary front elevational View thereof;

' FIGURE 3 is a fragmentary side elevational view of the same;

FlGURE 4 is a fragmentary front elevational view on an enlarged scale, showing, inter alia, the sectional impression roller, roller section holders and, by dotted lines, soleno'ds or electro-magnets for actuating the same;

FIGURE 5 is a fragmentary vertical sectional View, taken substantially in the plane of the line 5-5 in FIG- URE 4;

FIGURE 6 is a fragmentary sectional detail showing two of the roller sections and holders on their supporting shaft;

FIGURE 7 is a fragmentary perspective view showing an end portion of the supporting shaft;

FIGURE 8 is a fragmentary top plan view of the switch keyboard;

FIGURE 9 is a fragmentary vertical sectional view,

taken substantially in the plane of the line 9-9 in FIG URE 8; I FIGURE 10 is a fragmentary front elevational view of the keyboard;

FIGURE I1 is a wiring diagram of the electrical components used in the invention; and FIGURE 12 is a diagrammatic illustration showing an example of blocked out areas on a master sheet.

Referring now to the accompanying drawings in de-- tail, the general reference numeral 15 designates a suit able duplicating machine, including a suitable frame or housing 16 having a shaft 17 journalled therein to sup port the usual rotary cylinder 18. The shaft 17 is rotated in any suitable manner, such as for example, by gearing 19, it being understood that only those portions of the machine are illustrated which are concerned with the invention, while the arrangement of the other portions of the machine is conventional and requires no description or illustration herein.

In conventional practice a unitary impression roller is rotatably mounted on a shaft substantially under the cylinder for pressing a copy sheet against the master sheet which the cylinder carries, the cylinder usually being of metallic construction and the impression roller having a covering of rubber, or the like, for engaging the copy. However, in accordance with the invention, the impression roller is not unitary, but consists of a plurality of individual disc-like sections 20 which are disposed in substantial axial alignment on a rigid supporting shaft 21 mounted in the frame 16 longitudinally under the cylinder 18. Since the roller sections 20 are metallic, a covering of rubber, or the like, is preferably provided on the cylinder 18, as indicated at 18 in FIGURE 5.

or otherwise suitably secured therein, and. the portion of the roller section surrounding the bushing is slightly th'cker than its peripheral portion, so that when the several roller sections are assembled in contacting relation on the shaft 21, their peripheral portions are slightly spaced apart as shown in FIGURE 4, whereby to reduce friction between the adjacent roller sections when one is moved relative to another.

The shaft 21 has cylindrical end portions for mounting in the frame 16, but the intermediate portion of the shaft which carries the roller sections 20 is of a modified cross-section, having its lower half of a semi-cylindrical form corresponding in radius to the inside radius of the bushings 22, while its upper half is relieved as indicated at 21a in FIGURE 7, so that the top to bottom distance or thickness of the intermediate portion of the shaft is somewhat less than the inside diameter of the bushings. By virtue ,of this arrangement, the roller sections 2% are movable upwardly and downwardly on their rigid supporting shaft 21, that is, between the two positions shown in the left-hand and right-hand portions of FIGURE 6. Movement of the roller sections in a forward and backward direction on the shaft is prevented by the full radius of the lower half of the shaft as already noted, and when a roller section is moved upwardly to contact the cylinder 18 as shown in the left-hand portion of FIGURE 6, the lower half of its bushing is in supporting engagement with the complemental lower half of the shaft and sufficient area of bearing contact is thus available. On the other hand, if the roller section is lowered so that the upper part of its bushing is in contact with the relieved upper portion 21a of the shaft, the roller section is moved out of cooperating engagement with the cylinder by some distance as indicated at 23, and since under such conditions the rollersection is not subjected to rotation, its bearing contact with the shaft is relatively unimportant.

Each of the roller sections 20 is rotatably accommodated in a suitable holder 24 which, as is best shown in FIGURE 5, includes a pair of curved keeper members 24a, 24b and an elongated base member 240. A recess 24d exists between the members 24a, 24b in which the roller section is disposed, and an idler roller 25 is rotatably mounted on a pin 26 in the holder at the bottom of the recess 24d to engage the periphery of the roller section with the minimum of friction.

A pair of supporting rods 27 are provided in the frame 16 in parallel with and at opposite sides of the shaft 21, and the base portions 24c of the holders 24 are pivotally mounted on these rods in an alternate manner, one holder being pivoted on one rod, the next holder on the other rod, etc, so that only every second holder is pivoted on the same rod. Tubular spacers 28 are provided on the rods between the adjacent holders, as shown in FIGURE 4. The several holders may be individually and independently raised or lowered about their pivot rods, so as to correspondingly raise or lower the respective roller sections 25 in and out of cooperating relation with the cylinder 18. During their lowering movement, the roller sections are drawn downwardly by the free extremities of the members 24a, 24b of the respective holders, while upward movement of the roller sections is effected by the holders through the medium of the idler rollers 25, the roller sections being rotatably supported by the shaft 21 and entirely free to rotate in the holder recesses 24a.

The lowering of the holders is effected by individual solenoids or electro-nragnets 29 having reciprocable armatures 29a pivoted at 30 to connecting links 31 which, in turn, are pivoted at 32 to the base portions 240 of the holders 24, at points distant from the pivotal mounting of these base portions on the rods 27.

Since the windings of the electro-rnagnets 29 are of substantial thickness in comparison to the relatively thin holders 24, the electro-magnets or solenoids are arranged in several banks as shown in FIGURES 3 and 5, four such banks being shown for illustrative purposes, two on each side of the shaft 21. The connecting link 31 of one holder 24 is pivoted to the armature of a solenoid, for example, in

the upper left bank as viewed in FIGURE 5, the link of the next holder to a solenoid in the upper right bank, the link of the next holder to a solenoid in the lower left bank, the link of the next holder to a solenoid in the lower right bank, et cetera, so that the solenoids in each bank are spaced apart by a distance equivalent to the spacing of four adjacent holders, which distance is sufficient to provide clearance between the windings of the adjacent solenoids.

The solenoids are provided with apertured mounting ears 33 whereby they are secured to suitable mounting plates 34 in the frame 16 by suitable bolts or screws 35. These bolts or screws also serve as mounting means for a plurality of wire springs 36, one such spring being associated with each solenoid and having a free end poition 36a bearing upwardly against the pivot 36 so as to urge the link 31 upwardly and correspondingly urge the associated holder 24 upwardly on its pivot rod 27, thereby urging the associated roller section 20 upwardly into its cooperating relation with the cylinder 18. However, when the solenoid is energized, the link 31 is drawn downwardly against the action of the spring 36 and the roller section 20 is retracted from its operative engagement with the cylinder, as will be clearly understood.

Before proceeding to describe the control means for the several solenoids, an explanation should be given as to the relationship of the individual roller sections 20 to the master on the cylinder 18 and copies to he made therefrom.

For illustrative purposes it may be assumed that the master sheet 37, shown in FIGURE 12, is of legal size measuring 8 /2 x 13', and is placed on the cylinder 18 lengthwise, with its 13" dimension extending longitudinally of the cylinder. Allowing for a oneialf inch clear space at the top and bottom of the sheet, the working area of the sheet is 12 inches long, or 12 inches wide in terms of its extent horizontally of the machine, which is the position occupied by the cylinder. In FIGURE 12, the aforementioned half-inch clearances at the top and bottom of the sheet are indicated at 38, and the width of the working area is shown at 39.

Double-spaced lines of typewriting are one-third of an inch apart, thus making it possible to have thirty-six lines of typewritten data within the aforementioned l2-inch working dimension of the master sheet, corresponding to the thirty-six spaces or strips shown at 40, each one-third of an inch in width. On the basis of this arrangement the bushings 22 of the roller sections 20 are each one-third of an inch in width or thickness, whereby the several roller sections are in alignment with the respective spaces as of the master sheet 37 when the latter is positioned on the cylinder 18. Consequently, if all of the roller sections are permitted to be urged by their springs 36 against a copy sheet contacting the master, the data appearing in all of the spaces 40 on the master will be reproduced by impression on the copy during the duplicating procedure. However, if any one or more of the roller sections 20 are retracted from the cylinder by their respective solenoids 29, the particular space or spaces 40 of the master sheet will be effectively blocked out and prevented from making an impression on the copy. In this manner, any one or more of the spaces 49 of the master may be readily blocked out by simply energizing the appropriate solenoid or solenoids, 'as will be clearly understood.

It should be noted, of course, that the foregoing example of dimensions, line spacings, et cetera, is given for illustrative purposes only, and that the teachings of the invention are applicable to various different sizes of sheets, line spacings, etc., in the light of the proportions described,

specifically, that the impression roller is divided into as many sections as may reasonably be expected to be required for blocking out operations, each such section corresponding in width to the width of the individual area of the master which is to be blocked out, consistent with limitations of minimum dimensions in which the various parts of the invention can reasonably be made.

Novel control means are provided for energizing and de-energizing the various solenoids 29, these means being so arranged that control of the solenoids may be exercised either individually and independently of one another, or in groups. As such, the control means include a plurality of momentary contact switches 41 which are disposed in a keyboard arrangement on the frame or housing 16 of the machine. These switches are arranged in two superposed or vertically ofrset banks, each switch comprising, as is best shown in FIGURE 9, a relatively stationary contact member 42 and a relatively movable or depressible contact member 43. The member 43 is formed from resilient material and normally assumes a separated position from the member 42. The switch also includes a depressible actuating element or finger-piece 41a formed from resilient material, the element 41a being superposed on the switch member 43 and anchored therewith at one end, such as by a screw 44, to a common supporting bar 45 for the several switches in the same bank. Similarly, the contact member 42 of the switch is secured at one end to a common supporting bar 46 by a screw 47, the bars 4-5, 46 preferably being formed from suitable insulating material.

When the resilient finger-piece 41a of the switch is depressed, the contact members 42, 43 are brought together and flow of current through the switch is established, it being noted that the members 42, 43 are provided with wire leads 4%, 49, respectively, for placing them in circuit with a source of current and the associated solenoid 29, as will be hereinafter described.

It will be also noted that the finger-pieces 41a of the switches in the upper bank of the keyboard are somewhat wider than those in the lower bank and overlap the same, as illustrated. As such, the finger-pieces of all the switches in the two banks may be depressed individually and independently of one another, yet, one finger may be used for depressing a switch in the upper bank simultaneously with one or both adjacent switches in the lower bank. This arrangement is particularly useful when it is desired to block out two or three adjacent spaces of the master sheet simultaneously by the use of only one finger. To further afford this facility, the finger-pieces of the switches in the upper bank are somewhat shorter than those in the lower bank, as illustrated, the difference in length of the finger-pieces permitting convenient depression of any one switch, as well as a group of two or three.

The keyboard of switches is preferably disposed at the front of the machine on a supporting panel 59 which is located above the usual feed table or platform 51 on which copy sheets are fed to the cylinder 18. One switch is provided for controlling the operation of the particular solenoid 29 of each roller section 20, and the keyboard also includes an additional switch 52 which is used for cancelling the blocking out settings of the various switches 41, as will be hereinafter explained. The panel 50 has a depending, vertical portion 59a which extends downwardly toward the table 51 and is spaced from the latter by an extent sutiicient to permit passage of a copy sheet to the cylinder 18. The panel portion Silo is inscribed with reference lines 53, spaced apart by a width or distance corresponding to the width of the spaces 40 of the master sheet, and the lines 53 are suitably numbered as indicated at 54 so that the particular space on the master sheet which can be blocked out by the actuation of any particular switch may be easily identified. Moreover, suitable indicator lamps 55 are provided on the panel portion 58a in alignment with the respective reference lines 53, these lamps being in circuit with the respective switches as will be hereinafter described, whereby a lamp connected with a particular switch is energized when the switch is actuated, so as to indicate to the operator the particular space or area of the master sheet which is being blocked out.

Referring now to the wiring diagram of FIGURE 11,

7 E3 it will be noted that each switch 41 acturates the associated solenoid 29 through the medium of a relay 56, such a relay having a movable polepiece 56:: which normally rests against a pair of mutually insulated contacts 57, 58. A pair of mutually insulated contacts 59, 66 are provided in opposing relation to the contacts 57, 58, and when the relay is energized, the pole-piece 56a is separated from the contacts 57, 58 and brought against the contacts 59, 60. Current is supplied to the pole-piece by a conductor 61 and the contact 59 is connected to one side of the winding of the relay as indicated at 62, the leads 48, 49 of the switch 41 being connected to the relay in such manner that the switch is in parallel with the relay contacts 56a, 59. The other side of the relay winding is connected to the ground as shown at 63. As a result, when a particular switch 41 is actuated so as to close the same, current will travel from the supply conductor 61 through the connection 62 and through the relay winding to the ground 63, thus causing the relay to close and establish current flow through the contacts 56a, 59 again through the winding of the relay, whereby the relay remains closed even after depression of the momentary contact switch 41 is discontinued. The aforementioned indicator lamp 55 of the switch is connected in series with a suitable resistor 64 between the contact 59 and the ground 53, whereby the lamp is energized simultaneously with the closing of the relay.

The second contact side 56a, 60 of the relay is electrically separate from the side 56a, 5% and is used for closing the circuit through the solenoid 29 when the relay is closed, the solenoid being connected to the contact 60 as indicated at 65 and to the ground 63 as indicated at 66. It will be apparent from the foregoing that upon closing of any particular switch 41, the corresponding relay 56 will be closed and the corresponding indicator lamp 55 and solenoid 29 energized to retract, by the energization of the solenoid, the corresponding impression roller section 21! from its cooperating relation with the cylinder 18 to efiect blocking out of the corresponding area of the master sheet on the cylinder, the lamp 55 indicating the particular area which is being blocked out. As shown in FIGURE 11, the several switches, relays, lamps and solenoids are each connected. in parallel to afford their independent operation for each individual impression roller section.

It will also be appreciated from the foregoing that upon actuation of each switch 41, the associated relay 56 will remain closed and the associated roller section inactive (in its blocking out position), as long as current is being delivered through the supply conductor 61. Thus, means are provided for simultaneously cancelling the setting of all components such as may be in the blocking out position, the use of such cancelling means being desirable, for example, when a given run of copies has been made from a blocked out master and a different blocking out arrangement is to be used in a subsequent run.

These cancelling means include the aforementioned switch 52 which is in circuit with a relay 67, similar to the relays 56. The contacts 55a, 57 of the relay 67 are in series with the supply conductor 61 and a branch 68 extends from the supply conductor through the relay winding and switch 52 to the ground 63, as shown. In the inactive position of the relay 67, the contacts 56a and 57 are closed, thus facilitating flow of current to the relays 56 for the purpose of retracting the roller sections 20 from the cylinder 18, However, when the roller sections are to he returned to their operative positions against the cylinder, the switch 52 is simply depressed to close the circuit through the Winding of the relay 67', whereupon separation of the contacts 56a, 57 interrupts the flow of current to the relays 56 and simultaneously cancels the setting of all such roller sections which may have been in their blocking out positions.

The several relays 56 and the relay 67 together with their associated wiring are housed in a suitable compartment 59 on the machine frame or housing 16.

In the duplicating art certain conditions often arise when it is necessary or desirable to block out certain groups of the spaces 44) on repeated occasions after canceiling, and when the group to be blocked out includes a multiplicity of adjacent spaces, it would normally be necessary to depress as many of the switches 4i to correspond with the adjacent spaces in the group. The invention avoids this disadvantage by the provision of means for blocking out the several adjacent spaces in the group by the depression of only one switch, as will be presently described.

These means involve the provision of another set of manually actuated switches 7 which are arranged in a single bank at the front of the machine adjacent the switch keyboard 41 and are appropriately numbered as indicated at 71, to correspond with the aforementioned reference lines 53.

The switches 70 are bridged in series across the switches 41, as for example, across the leads 48 of the switches 41, so that When, for example, the three switches 70 shown in FIGURE 11 are closed, the relays 56 are energized simultaneously upon closing any single one of the switches 41. Thus, in practice, when it is desired to block out, for example, ten adjacent spaces of the master sheet, the ten switches 78 corresponding to those spaces are closed and the blocking out operation is effected simply by closing any one of the ten switches 41 in the group. Upon cancellation of the ten block outs by the switch 52, the same ten spaces may again be blocked out by closing of any one of the ten switches 41, as long as the ten switches 76) are still closed. The switches 70, of course, are of a conventional type adapted to remain either open or closed, and shifted manually from one position to the other.

The arrangement of this invention described provides for blocking out of the required area of the master manually by the operator of the machinethrough manipulation of the appropriate switches. However, it is also within the concept of the invention to provide for automatic blocking out, such as for example, by utilizing photoelectric cell means or some other conventional scanning device in conjunction with perforations, opaque markings or other suitable means detectable by the scanning device, on the leading edge portion of each copy sheet which is inserted into the machine. In such an arrangement the scanning device means are in circuit with the relays 56 in substitution for the switches 41, and the blocking out of any particular space of the master is effected automatically when the aperture or other marking on the leading edge of the copy sheet is detected by the scanning means. The apertures or other mark ings, of course, are co-ordinatcd on the copy sheet in relation with or to the respective spaces or areas of the master which they block, and by having such markings spaced inwardly from the leading edge of the copy sheet, it is possible to block out only that portion of the space disposed between the marking and the trailing edge of the sheet. In this arrangement of the invention the use of the switches 41, 79 is completely eliminated, while the indicator lights 55 are also unnecessary in view of the automatic operation involved. The cancelling switch 52 may also be arranged for automatic closing with the passage of each copy sheet out of the machine.

While in the foregoing there has been shown and described the preferred embodiment of the invention, various modifications may become apparent to those skilled in the art to which the invention relates. Accordingly, it is not desired to limit the invention to this disclosure and various modifications may be resorted to, such as may lie within the spirit and scope of the appended claims.

What is claimed as new is:

1. In a duplicating machine, the combination of a cylinder, an impression roller provided adjacent said cylinder for cooperation therewith and comprising a plurality of individual sections disposed in substantial axial alignment longitudinally of the cylinder, a rigid supporting shaft for said roller sections, said roller sections being formed with circular openings at the center thereof to receive said shaft, said shaft having a semi-cylindrical bottom portion conforming in radius to said openings and a relieved upper portion whereby the vertical sectional dimension of the shaft is less than the diameter of said openings and whereby the roller sections may be individually and independently moved upwardly and downwardly on said shaft, and means for moving said roller sections.

2. In a duplicating machine, the combination of a cylinder, an impression roller provided adjacent said cylinder for cooperation therewith and comprising a plurality of individual roller sections disposed in substantial axial alignment longitudinally of said cylinder, said roller sections being provided with central openings, a common rigid supporting shaft for said roller sections extending through said openings, said openings being larger than a cross-sectional dimension of said shaft whereby said roller sections may be individually and selectively moved radially of the shaft toward and away from said cylinder, and means for moving the individual roller sections radially relative to said shaft.

3. In a duplicating machine, the combination of a cylinder, an impression roller provided adjacent said cylinder for cooperation therewith and comprising a plurality of individual roller sections disposed in substantial axial alignment longitudinally of said cylinder, said roller sections being provided with central openings, a common rigid supporting shaft for said roller sections extending through said openings, said openings being larger than a cross-sectional dimension of said shaft whereby the roller sections may be individually and selectively moved radially of the shaft toward and away from said cylinder, a plurality of movably mounted holders for the respective roller sections, resilient means connected to said holders for urging the same in a direction to move the roller sections radially of said shaft toward said cylinder, and independently and individually actuable means connected to said holders for moving the roller sections away from the cylinder against the action of said resilient means.

4. The device as defined in claim 3 wherein said last mentioned means include a plurality of electro-magnets having movable armatures operatively connected to the respective holders, and means for actuating said electromagnets independently of one another.

5. The device as defined in claim 3 wherein said last mentioned means include a plurality of electro-rnagnets having movable armatures operatively connected to the respective holders, and a plurality of independently actuable switches in circuit with the respective electro-magnets and a source of current.

6. In a duplicating machine, the combination of a frame, a rotary cylinder supported by said frame, an impression roller provided adjacent said cylinder for cooperation therewith and comprising a plurality of individual roller sections disposed in substantial axial alignment longitudinally of said cylinder, said roller sections being provided with central openings, a common rigid supporting shaft for said roller sections extending through said openings, said openings being larger than a cross-sectional dimension of said shaft whereby the roller sections may be individually and selectively moved radially of the shaft toward and away from said cylinder, a plurality of holders for the respective roller sections pivotally mounted on said frame for movement about an axis parallel to the cylinder and corresponding movement of the roller sec-' holders for urging the same and the roller sections toward said cylinder, and a plurality of switches in circuit with a source of current and with the respective electromagnets for energizing the latter to move said holders and the roller sections away from the cylinder against the action of said resilient means.

7. The device as defined in claim 6 wherein said switches are arranged in a keyboard on said frame comprising two superposed switch banks, each switch having a depressihle actuating element, and the actuating elements of the switches in the upper bank overlapping those of the switches in the lower bank, whereby a switch in the upper bank may be actuated simultaneously with at least one adjacent switch in the lower bank by the use of only one finger.

8. In a duplicating machine, the combination of a cylinder, an impression roller provided adjacent said cylin der for cooperation therewith and comprising a plurality of individual roller sections disposed in substantial axial alignment longitudinally of said cylinder, said roller sections being provided with central openings, a common rigid supporting shaft for said roller sections extending through said openings, said openings being larger than a cross-sectional dimension of said shaft whereby the roller sections may be individually and. selectively moved radially of the shaft toward and away from said cylinder, a plurality of eiectro-magnets operatively connected to the respective roller sections for moving the same radially of the shaft, a plurality of relays in circuit with the respective electro-rnagnets, and a plurality of switches in circuit with the respective relays and with a source of current.

9. The device as defined in claim 8 together with cancelling switch means in circuit with the source of current and said relays.

10. The device as defined in claim 8 together with a second set of switches bridging the first mentioned switches in series, whereby a predetermined group of said relays may be energized simultaneously by actuation of only one switch in the first mentioned set.

References Cited in the file of this patent UNITED STATES PATENTS 

